Regent Honeyeater's Lost Song Rediscovered Through Wild Bird Tutors
In a remarkable conservation breakthrough, the critically endangered regent honeyeater has rediscovered its lost song, with wild-born birds successfully teaching the complete version to zoo-bred males. This development offers new hope for the survival of one of Australia's rarest avian species, which has seen its population plummet to fewer than 250 individuals in the wild.
Once thriving in vast flocks across south-eastern Australia, from Queensland to Kangaroo Island in South Australia, the regent honeyeater is now largely confined to the Blue Mountains region. As numbers have dwindled over recent decades, so too has the complexity of the bird's song, with the typical tune replaced by a simpler, shorter version containing only half the original syllables.
Conservation Efforts and Song Tutoring Program
A dedicated team of researchers has intervened to rescue the song from the brink of extinction. Using a combination of recordings and direct instruction from two wild-born male "song tutors," scientists have taught young zoo-bred regent honeyeaters their original wild call. This song plays a crucial role in attracting mates and establishing territory, making its restoration vital for breeding prospects.
The captive breeding program at Taronga Zoo in Sydney, ongoing since 1995, provided the foundation for this initiative. Over a three-year period starting in the 2020-21 breeding season, efforts focused on teaching young males the full song. Initially, researchers played recorded songs daily for the first six months of the birds' lives, but this approach proved unsuccessful.
Breakthrough with Wild Tutors
In the second year, the team introduced two wild-born males as singing teachers, achieving greater success. Dr Daniel Appleby of the Australian National University, the study's first author, explained, "We took fledgling birds from all different parents, and we creched them with a wild male who sang correctly." However, they discovered that class size mattered significantly. "We realised that if you have too many birds to one tutor – so a big class size – they don’t learn as effectively," Appleby added.
By the third year, song class sizes were reduced to about six juvenile males per adult male tutor. This adjustment led to a dramatic improvement, with the proportion of juveniles learning the wild song increasing from zero to 42% within three years. Notably, the full version of the wild song had disappeared from the wild during the study, making the zoo population the sole remaining source of this traditional song culture.
Impact and Future Goals
Subsequently, zoo-bred males that mastered the complete song have taught it to the next generation. Ecologist Dr Joy Tripovich, who studies regent honeyeaters at both the Taronga Conservation Society and the University of New South Wales, described hearing the restored song for the first time as "really exciting." Since 2000, Taronga and its partners have released 556 zoo-bred regent honeyeaters into New South Wales and Victoria, including males who have learned their original song.
More research is underway to assess the impact of the song tutoring program on the success of birds released back into the wild. Tripovich emphasized, "Our aim for the overall project is to have species become self-sustaining. We really want them to grow their numbers on their own so that we don’t need to intervene any more." The researchers hope that restoring the song will improve breeding success and overall fitness, with the ultimate goal of seeing wild and captive birds interbreed, a phenomenon rarely observed historically.
The findings, published in the journal Nature Scientific Reports, highlight a innovative approach to wildlife conservation that could have broader applications for other endangered species facing similar challenges.
